The South Georgia Pipit (ARKive) breeds farther south than any other songbird. The South Georgia Pintail Anas georgica (IBC) is sometimes considered distinct from the more widespread Yellow-tailed Pintail Anas spinicauda.
Marine fish known exclusively from South Georgia include the Antarctic Sculpin Bathylutichthys taranetzi (FishBase), the sole member of the family Bathylutichthyidae. Other endemic marine fish include the Antarctic dragonfish Parachaenichthys georgianus (FishBase) and Psilodraco breviceps (MNHN), the South Georgian Plunderfish Artedidraco mirus (FishBase), the Permitin Spiny Plunderfish Harpagifer permitini (FishBase), and a cod icefish Trematomus vicarius (BHL).
Arthropods unique to South Georgia include the perimylopid beetles Hydromedion sparsutum (flickr) and Perimylops antarcticus (flickr), a water beetle Lancetes claussi (flickr), a midge Eretmoptera murphyi (flickr), a chalcidoid wasp Notomymar aptenosoma (Bishop Museum 4 MB pdf file), and a spider Notiomaso grytvikensis (South Georgia Newsletter).
Endemic marine molluscs include Amauropsis powelli (Antarctic Invertebrates), Brookula exquisita (p. 4 of MNHN pdf file), Lissotesta (or Submargarita) notalis (fig. 18 at BHL), Chlanidota paucispiralis (eol), Margarella tropidophoroides (Femorale), Proneptunea duplicarinata (fig. 13 at BHL), Trophon cribellum (fig. 45 at BHL), and Skenella wareni (fig. C on p. 24 of nhm.org 6 MB pdf file). An isopod crustacean Dolichiscus diana (Antarctic Invertebrates) is also known only from South Georgian waters.
There are no endemic vascular plant species (the sedge previously known as Uncinia smithii is a synonym of Uncinia macrolepis) although there are a few endemic lichens and bryophytes, such as Cephalozia skottsbergii (JSTOR). There are four endemic algae species (Internet Archive).
South Georgia is an overseas territory of the United Kingdom and part of the Scotia Sea Islands Tundra terrestrial ecoregion (EoE). Information on levels of endemism for marine species can be found at (PLos ONE).